Definitely leave it where it is

trying to remove the byssal threads from the bottom of the glass in the tank will be a nightmare haha my t. maxima is further away from the light and was under much less light when I had led's but has always looked gorgeous
It appears to be a t. maxima, there's a few things that say this:
- The row of tightly-spaced line of eyes that are running around the edge of the mantle.
- The scutes are fairly well pronounced and even like common with t. maxima but that can also be a common feature in t. crocea that haven't burrowed, these are usually much thinner and delicate though.
- (From what I can see) The distribution of the eye-tipped tubercles seems to be the common t. maxima layout, t. crocea can also share this which is why they can be so hard to distinguish.
- One of the other bigger distinguishing features is the lined patterned of the mantle, it's very uncommon you get a t. crocea that has a solid colour with thin radiating lines on the mantle.
A couple of pics that you could take that would absolutely nail this ID is:
- Take one from front on so we can see the shape of the shell, t. maxima are thinner and don't have a "bulge" towards the byssal opening like t. crocea do.
- Another one of the inlet siphon, that shows the small tentacles lining the siphon.
- A side shot of just the shell so you can see the shape of the shell as they both have some features that are able to help.
- A picture of the upper shell margin as t. maxima has a much more pointed shell (almost triangular) and t. crocea has a very smooth margin.
Even without the pics I'm 90% sure that's a t. maxima

in terms of the growth issue can you take a pic of the newest scutes that it has grown so we can see the size and colour of them. No one has been picking at it and the foot looks nice and healthy if you're able to see it?